public static byte[] AddSignatureAndMac(byte[] bytes, string sharedSecret)
{
TimeSpan sinceMidnight = DateTime.Now - DateTime.Today;
int timez = (int)sinceMidnight.TotalMilliseconds;
bytes = ByteHelper.ConcatinateArray(BitConverter.GetBytes(timez), bytes); // Add a milisecond timestamp to the meassage.
byte[] macBytes = Convert.FromBase64String(CreateMac(bytes, sharedSecret));
byte[] singatureBytes = new byte[] { 0x92, _version }; // Signature byte and version byte.
bytes = ByteHelper.ConcatinateArray(singatureBytes, macBytes, bytes);
return(bytes);
}
public static byte[] MessageTransmissionHandler(Message message)
{
byte[] textBytes = new byte[0];
if (!String.IsNullOrEmpty(message.Text))
{
textBytes = Encoding.Unicode.GetBytes(message.Text);
}
byte[] dataBytes = new byte[0];
if (message.Data != null)
{
dataBytes = message.Data;
}
byte[] messageBytes = ByteHelper.ConcatinateArray(BitConverter.GetBytes(message.From), new byte[] { (byte)message.Type });
messageBytes = ByteHelper.ConcatinateArray(messageBytes, dataBytes, textBytes);
return(messageBytes);
}
private static void Keepalive() // Threaded looping method.
{
try
{
while (_loggedIn)
{
Thread.Sleep(500);
List <ContactObj> onlineContacts = _contacts.FindAll(x => x.Online == true);
byte[] contactIds = new byte[0];
foreach (ContactObj contact in onlineContacts)
{
byte[] contactId = BitConverter.GetBytes(contact.ID);
contactIds = ByteHelper.ConcatinateArray(contactIds, contactId);
}
ChatTwo_Client_Protocol.MessageToServer(ChatTwo_Protocol.MessageType.Status, contactIds, null);
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("### " + _threadKeepalive.Name + " has crashed:");
System.Diagnostics.Debug.WriteLine("### " + ex.Message);
System.Diagnostics.Debug.WriteLine("### " + ex.ToString());
}
}
private static string CreateMac(byte[] messageBytes, string sharedSecret)
{
return(ByteHelper.GetHashString(ByteHelper.ConcatinateArray(ByteHelper.GetHashBytes(messageBytes), Convert.FromBase64String(sharedSecret))));
}
/// <summary>
/// Create an ACK packet from a base64 hash string.
/// </summary>
/// <param name="hash">Base64 hash string to be used.</param>
protected byte[] CreateAck(string hash)
{
byte[] ackTag = new byte[] { 0xCE }; // 0xCE = 206
byte[] ackBytes = ByteHelper.ConcatinateArray(ackTag, Convert.FromBase64String(hash), ackTag);
return(ackBytes);
}